Moving Button
import java.awt.Color; import java.awt.Graphics; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; import javax.swing.Timer; /* * MovingButton.java * * Created on May 2, 2007, 4:17 PM * * Copyright (c) 2007, Sun Microsystems, Inc * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * Neither the name of the TimingFramework project nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** * * @author Chet */ public class MovingButton extends JButton implements ActionListener { Timer timer; // for later start/stop actions int animationDuration = 2000; // each animation will take 2 seconds long animStartTime; // start time for each animation int translateY = 0; // y location of the button static final int MAX_Y = 100; /** Creates a new instance of TranslucentButton */ public MovingButton(String label) { super(label); setOpaque(false); timer = new Timer(30, this); addActionListener(this); } /** * Displays our component in the location (0, translateY). Note that * this changes only the rendering location of the button, not the * physical location of it. Note, also, that rendering into g will * be clipped to the physical location of the button, so the button will * disappear as it moves away from that location. */ public void paint(Graphics g) { g.translate(0, translateY); super.paint(g); } /** * This method handles both button clicks, which start/stop the animation, * and Swing Timer events. */ public void actionPerformed(ActionEvent ae) { if (ae.getSource().equals(this)) { // button click if (!timer.isRunning()) { animStartTime = System.nanoTime() / 1000000; this.setText("Stop Animation"); timer.start(); } else { timer.stop(); this.setText("Start Animation"); // reset translation to 0 translateY = 0; } } else { // Timer event // calculate the elapsed fraction long currentTime = System.nanoTime() / 1000000; long totalTime = currentTime - animStartTime; if (totalTime > animationDuration) { animStartTime = currentTime; } float fraction = (float)totalTime / animationDuration; fraction = Math.min(1.0f, fraction); // This calculation will cause translateY to go from 0 to MAX_Y // as the fraction goes from 0 to 1 if (fraction < .5f) { translateY = (int)(MAX_Y * (2 * fraction)); } else { translateY = (int)(MAX_Y * (2 * (1 - fraction))); } // redisplay our component with the new location repaint(); } } private static void createAndShowGUI() { JFrame f = new JFrame("Moving Button"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setSize(300, 300); JPanel checkerboard = new Checkerboard(); checkerboard.add(new MovingButton("Start Animation")); f.add(checkerboard); f.setVisible(true); } public static void main(String args[]) { Runnable doCreateAndShowGUI = new Runnable() { public void run() { createAndShowGUI(); } }; SwingUtilities.invokeLater(doCreateAndShowGUI); } /** * Paints a checkerboard background */ private static class Checkerboard extends JPanel { private static final int DIVISIONS = 10; static final int CHECKER_SIZE = 60; public void paintComponent(Graphics g) { g.setColor(Color.white); g.fillRect(0, 0, getWidth(), getHeight()); g.setColor(Color.BLACK); for (int stripeX = 0; stripeX < getWidth(); stripeX += CHECKER_SIZE) { for (int y = 0, row = 0; y < getHeight(); y += CHECKER_SIZE/2, ++row) { int x = (row % 2 == 0) ? stripeX : (stripeX + CHECKER_SIZE/2); g.fillRect(x, y, CHECKER_SIZE/2, CHECKER_SIZE/2); } } } } }